This invention relates to an apparatus connected between a personal computer (PC) and instruments, particularly to an RS-232/RS-485 data transmission converter where each can be provided with a unique identity code for facilitating the communication therebetween.
Nowadays, using a personal computer (PC) to process information from various instruments or equipment is a commonly used skill. An RS-232 standard interface has to be connected between the PC and each of the instruments so as to form a communication path. If a remote communication is required, an RS-485 standard interface will be necessary. Thus, two RS232/RS485 converters are required for converting the communication between RS232 and RS485 standards. Therefore, the complexity and the costs for interfacing the PC and the instruments have been greatly increased. Further, as transmission directions of the RS232/RS485 converters have to be controlled by the PC and cannot operate in an automatic switching mode, this is an additional burden to the PC and it will also easily cause incorrect messages to occur when operating in a multitask mode.